Germination phenology and restoration potential of
some Great Basin native annual forb species
Tara Forbis, USDA-ARS
Elizabeth Leger and Erin Goergen, UNR
Susan E. Meyer, RMRS
Current restoration practices
• primarily late seral
species
• mismatch between
successional timescale
and restoration projects’
timescales
• success rates are often
low
• could the inclusion of
early successional
species improve
restoration success?
Can native annuals facilitate restoration of Great
Basin plant communities?
•
•
•
sometimes abundant in
disturbances
some species structurally
and phenologically similar
to cheatgrass
invaders sometimes
resisted by natives that
occupy the same niche
(limiting similarity)
• 2 initial questions:
– Can we identify native annuals with
germination phenology similar to that of
cheatgrass?
– Can we identify native annuals that can
effectively compete with cheatgrass?
Germination phenology of annuals
• dormancy is key to life history of annual plants
• timing of germination can be key in determining
competitive interactions
• cheatgrass is a facultative winter annual:
– dormant at dispersal, lost through dry after-ripening
fall
winter
spring
facultative winter
annuals
obligate winter
annuals
summer
spring
annuals
Can we identify native annuals with germination
phenology similar to cheatgrass?
Laboratory studies of germination phenology
• Amsinckia menziesii var. intermedia (Boraginaceae)
• Amsinckia tesselata (Boraginaceae)
• Blepharipappus scaber (Asteraceae)
• Descurainia pinnata (Brassicaceae)
• Eriastrum sparsiflorum (Polemoniaceae)
• Lappula occidentalis (Boraginaceae)
• Mentzelia veatchiana (Loasaceae)
• Plagiobothrys tenellus (Boraginaceae)
dark
light
cold
dry
stratification after-ripening
dormancy assessment, simulated summer and winter,
4 week pre-treatment
no pre-treatment
Viability testing is important in determining seed
dormancy status…
germination
viability
testing
Germination phenology: potential fall germinators
Germination phenology: likely spring germinators
Germination phenology of Great Basin native
annuals: field studies
• with Dr. Susan Meyer, RMRS
• 5 blocks at one site to be retrieved monthly for a year, then
in spring and fall for 3 more years
• When does each species germinate? Does dormancy
cycle?
• Amsinckia menziesii var. intermedia (Boraginaceae)
• Amsinckia tesselata (Boraginaceae)
• Blepharipappus scaber (Asteraceae)
• Mentzelia albicaulis (Loasaceae)
• Mentzelia veatchiana (Loasaceae)
seed
bags
litter + screen cover
germinants in bags
Artificial seed bank preliminary results
120
germinable
field germ
Amsinckia menziesii var. intermedia
Percent germination
100
germinants observed
80
60
40
20
0
Sept
Oct
Nov
Dec
Artificial seed bank preliminary results
120
Amsinckia tesselata
germinable
field germ
Percent germination
100
80
germinants observed
60
40
20
0
Sept
Oct
Nov
Dec
Artificial seed bank preliminary results
120
germinable
field germ
Blepharipappus scaber
Percent germination
100
80
60
40
20
0
Sept
Oct
Nov
Dec
Artificial seed bank preliminary results
120
germinable
field germ
Mentzelia albicaulis
Percent germination
100
80
60
40
20
0
Sept
Oct
Nov
Dec
Artificial seed bank preliminary results
120
germinable
field germ
Mentzelia veatchiana
Percent germination
100
80
60
40
20
0
Sept
Oct
Nov
Dec
Competition between cheatgrass and native
annuals: greenhouse study
• With Drs. Elizabeth Leger and Erin Goergen, UNR
• Hybrid additive/replacement design with Bromus
competing with
– Bromus
– Amsinckia + Bromus
– Mentzelia + Bromus
• Facilitation of Elymus by native annuals in cheatgrass
Competition between cheatgrass and native
annuals: results
Competition between cheatgrass and native
annuals: field study
Elymus or Bromus performance in:
• Bromus
• Amsinckia menziesii var. intermedia (Boraginaceae)
• Amsinckia tesselata (Boraginaceae)
• Blepharipappus scaber (Asteraceae)
• Descurainia pinnata (Brassicaceae)
• Mentzelia veatchiana (Loasaceae)
Conclusions
• Amsinckia, Descurainia, and Lappula have
the potential to germinate in fall (lab study)
• Amsinckia and Blepharipappus appear to
be nondormant in fall (seedbank study)
• Amsinckia can compete with Bromus as
effectively as Bromus itself, while Mentzelia
is a weak competitor (greenhouse study)
• Some of these species may be useful in
restoration
Acknowledgements
Great Basin Native Plant Selection and Increase Project
Jamie Roice, Bill Raitter, Tricia Bobo
ARS Range and Pasture Program